1. Field of the Invention
The invention relates to a daughter circuit board of a Brushless DC motor (hereinbelow referred to as BLDC motor) for interface signal conversion.
2. Description of the Related Art
As shown in FIGS. 1 and 2, a conventional electronically commutated motor (ECM) includes a main body and a controller. The main body has a stator assembly and a rotor assembly. The controller should correspond with both the main body and a control interface of a control system of a user terminal. Different control systems of user terminals correspond with different control signals. For example, both a control system of an air-conditioner and a control system of a washing-machine belong to control system of user terminals, but the control signals thereof are completely different. Conventionally, for each specific control system of a user terminal, a motor and a controller thereof are developed accordingly, which, however, brings about the following disadvantages: 1) a variety of motors have to be manufactured, which results in inconvenient management and standardization; 2) the development for motors takes time and increases the production costs; and 3) the newly-developed motor has a narrow application scope and is inconvenient for popularization.
To solve the above-described problems, a motor controller including a mother circuit board and a daughter circuit board butted therewith has been introduced. Main functional circuits of the motor controller are disposed on the mother circuit board. Different interface circuit units and identify circuits are disposed on different daughter circuit boards. When one daughter circuit board is butted with the mother circuit board, the identify circuit of the daughter circuit board sends messages to a central control and process unit of the mother circuit board. Thereafter, the central control and process unit automatically assigns an input/output port for the daughter circuit board. Thus, through cooperation with various daughter circuit boards, the motor controller can be applied to various occasions, i.e., has a wide application. Consequently, the motor manufactures do not need to produce a large number of motors, thereby reducing the management and development costs, simplifying the production process, and improving the efficiency.
Specifically, as shown in FIGS. 3-5, a motor controller includes a central control and process unit, an interface circuit unit, and an identify circuit. The central control and process unit is disposed on a mother circuit board. The interface circuit unit and the identify circuit are disposed on a daughter circuit board. The mother circuit board and the daughter circuit board are butted with each other to form an electric connection. The identify circuit inputs an identify signal to the central control and process unit, and then the central control and process unit automatically assigns an input/output port for the interface circuit unit according to the identify signal.
Identify circuits corresponding with different interface circuit units output different signals, whereby forming different daughter circuit boards. An output end of the central control and process unit is connected to a power drive circuit module. An input end of the central control and process unit is connected to an output end of a rotor position sensing circuit. The power drive circuit module and the rotor position sensing circuit are disposed on the mother circuit board. A power supply circuit and an analog sensing circuit are also disposed on the mother circuit board. The power supply circuit supplies power to all the circuits. The central control and process unit is a CPU, a micro control unit (MCU), or a digital signal processor (DSP). A port 3 is disposed on the mother circuit board and includes eleven terminal lugs E, N, L, M1, M2, M3, M4, M5, M6, M7, and M8. There may be a plurality of daughter circuit boards, for example, a first daughter circuit board, a second daughter circuit board, and a third daughter circuit board. A slot 1 is disposed on the mother circuit board, and a plug connector 2 is disposed on the daughter circuit board. The plug connector 2 is received in the slot 1 whereby electrically connecting the daughter circuit board with the mother circuit board.
To standardize the signal mode of daughter circuit boards and benefit the correspondence thereof with various control systems of user terminals, it's necessary to standardize reasonably the daughter circuit boards to form a basically consistent electric standard so as to facilitate management and application.